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  • 1
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 89 (2001), S. 7505-7507 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: We theoretically study the spin-polarized current flowing through a Josephson junction (JJ) in a spin injection device. When the spin-polarized current is injected from a ferromagnet in a superconductor (SC), the charge current is carried by the superconducting condensate (Cooper pairs), while the spin-up and spin-down currents flow in equal magnitude but in the opposite direction in a SC, because of no quasiparticle charge current in the SC. This indicates that not only the Josephson current but also the spin current flow across JJ at zero bias voltage, thereby generating Joule heating by the spin current. The result provides a new method for detecting the spin current by measuring Joule heating at JJ. © 2001 American Institute of Physics.
    Materialart: Digitale Medien
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  • 2
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 87 (2000), S. 805-813 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The hysteresis loop of plastically deformed Fe metals and alloys was measured for single crystals, polycrystalline iron, and A533B steel samples, and the dislocation density and structure of these samples were observed by electron microscopy. The relation between structure-sensitive properties and applied stress σ was analyzed in connection with grain boundaries and dislocations. The coercive force Hc increases with σ and is represented by one curve in all the samples. The magnetic susceptibility χc above the coercive field can be described by a simple relation to the magnetic field H. χc=c/H3 in a limited region of H. The parameter c depends only on lattice defects such as dislocations and the grain size and has a simple relation to them, but is independent of the kinds of samples or of the process of plastic deformation. The susceptibility χc is explained in comparison with the susceptibility χr in the range of approach to saturation. The magnetic properties c and Hc are discussed considering the dislocation density and its distribution including the effect of grain boundaries. These magnetic properties are useful for nondestructive tests of metal fatigue. © 2000 American Institute of Physics.
    Materialart: Digitale Medien
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  • 3
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 87 (2000), S. 5227-5229 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: We theoretically study the spin-dependent transport in a ferromagnet–superconductor–ferromagnet double barrier tunnel junction. The spin-polarized tunneling currents give rise to spin imbalance in the superconductor. The resulting nonequilibrium spin density suppresses the superconductivity with increase of the tunneling currents. We focus on the effect of asymmetry in the double tunnel junction, where the barrier height of the tunnel junction and the spin polarization of the ferromagnets are different, on spin injection, and discuss how the superconductivity is suppressed in the asymmetric junction. Our results explain recent experimental results on the critical current suppression in high-Tc superconductors by spin injection. © 2000 American Institute of Physics.
    Materialart: Digitale Medien
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  • 4
    Digitale Medien
    Digitale Medien
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 78 (2001), S. 515-517 
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: We have fabricated granular nanobridge structures consisting of electrodes separated by a nanometer-sized gap in which a thin insulating CoAlO granular film is filled, and measured the current–bias voltage characteristics in a magnetic field to investigate the spin-dependent transport. The Coulomb blockade with a clear threshold voltage (Vth) is observed at 4.2 K. Tunnel magnetoresistance (TMR) is enhanced by fabricating nanobridges. TMR shows a maximum exceeding about 30% at the voltage slightly above Vth. This enhancement is explained by the orthodox theory of single electron tunneling in ferromagnetic multiple tunnel junctions. © 2001 American Institute of Physics.
    Materialart: Digitale Medien
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  • 5
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Science Ltd
    British journal of dermatology 144 (2001), S. 0 
    ISSN: 1365-2133
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Recently, it has been proposed that viral infection is involved in the pathogenesis of hypersensitivity syndrome. Cytomegalovirus (CMV), one of the aetiological agents of infectious mononucleosis, has never been reported as an organism associated with hypersensitivity syndrome. We describe a 64-year-old man with severe phenytoin-induced hypersensitivity syndrome associated with CMV infection. Twenty-five days after the patient was started on phenytoin, he developed high fever and a generalized erythematous rash followed by jaundice, renal failure and disseminated intravascular coagulopathy (DIC). CMV-specific IgG antibodies were significantly increased 7 weeks after the onset of clinical symptoms and the increase was associated with the appearance of CMV-specific IgM. CMV DNA was detected in the serum of the patient. Coinfection with other viruses, such as Epstein–Barr virus and human herpesviruses 6 and 7, could be excluded because antibody titres to those viruses did not increase during the clinical course of his illness. We suggest that reactivation of CMV may contribute, at least in some cases, to the development of hypersensitivity syndrome.
    Materialart: Digitale Medien
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  • 6
    ISSN: 1365-2036
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: The clinical significance of Helicobacter heilmannii infection remains uncertain, owing to the lack of a specific detection method. Recently, we reported a marked increase in myofibroblasts in the early stage of Helicobacter pylori infection in Monglian gerbils.〈section xml:id="abs1-2"〉〈title type="main"〉Aim:The present study was designed to clarify changes in myofibroblasts, and in the immunoeactivities of basic fibroblast growth factor, cyclooxygenase-2 and inducible nitric oxide synthase after H. pylori infection in Monglian gerbils and H. heilmannii infection in mice.〈section xml:id="abs1-3"〉〈title type="main"〉Methods:After oral inoculation, changes in the location of bacteria and the immunoreactivity of myofibroblasts, basic fibroblast growth factor, cyclooxygenase-2 and inducible nitric oxide synthase were stained with the indirect immunofluorescent method and observed by confocal laser microscopy.〈section xml:id="abs1-4"〉〈title type="main"〉Results:In H. heilmannii-infected mice, the increases in myofibroblasts and in immunoreactivities of these three markers were sustained 12 months after infection. In H. pylori-infected Monglian gerbils, however, these increases were significant at 3 months but had returned to control levels at 12 months.〈section xml:id="abs1-5"〉〈title type="main"〉Conclusions:Two types of Helicobacter infection showed different patterns of myofibroblast proliferation, coinciding with the extent of inflammation. These findings suggest that this difference may be related to the consequences of the infection.
    Materialart: Digitale Medien
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  • 7
    Digitale Medien
    Digitale Medien
    Oxford, UK : Munksgaard International Publishers
    Journal of oral pathology & medicine 33 (2004), S. 0 
    ISSN: 1600-0714
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Background:  The purpose of the present study was to elucidate whether myoepithelial cells proliferate mitotically during regeneration of rat submandibular glands after atrophy.Methods:  The excretory duct of the right submandibular gland of rats was doubly ligated near the hilum with metal clips, which were removed after 7 days of ligation (day 0). The regenerating right submandibular glands were removed from 0 to 14 days after removal of the clips. The removed tissue was examined with immunohistochemical double staining for proliferating cell nuclear antigen (PCNA) as a marker of proliferating cells and actin as a marker of myoepithelial cells, as well as with transmission electron microscopy (TEM).Results:  The PCNA-positive myoepithelial cells were observed at the periphery of transitional duct-acinar structures, ducts and acini in the regenerating glands at every time-point, and the PCNA-labeling index of myoepithelial cells increased greatly especially between day 2 and 4. The mitosis of myoepithelial cell was also identified by TEM at day 4.Conclusion:  These findings suggest that myoepithelial cells are able to proliferate mitotically during regeneration of rat submandibular gland.
    Materialart: Digitale Medien
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  • 8
    Digitale Medien
    Digitale Medien
    Oxford, UK : Munksgaard International Publishers
    Journal of oral pathology & medicine 32 (2003), S. 0 
    ISSN: 1600-0714
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Background:  The present study was aimed to determine the proliferation and distribution of myoepithelial cells during atrophy of rat sublingual glands.Methods:  The excretory duct of the right sublingual gland of rats was doubly ligated with metal clips to induce atrophy in the gland. The atrophic sublingual glands were taken from 1 to 28 days after duct ligation and examined with single immunohistochemistry for actin as a marker of myoepithelial cells and with immunohistochemical double staining for actin and proliferating cell nuclear antigen (PCNA) as a marker of proliferating cells.Results:  In unligated sublingual glands, myoepithelial cells embraced acini and intercalated ducts, but not striated and interlobular excretory ducts. In the early stages of atrophy, myoepithelial cells surrounded small ducts but not large ones. However, in the later stages of atrophy, myoepithelial cells were also observed at the periphery of the large ducts. The immunohistochemical double staining showed that there were PCNA-positive myoepithelial cells in the normal as well as in the atrophic sublingual glands. However, the PCNA labeling indices of myoepithelial cells were low in the unligated and atrophic sublingual glands, and there were no statistically significant differences in these labeling indices.Conclusion:  The observations suggest that the distribution of myoepithelial cells change during atrophy of rat sublingual glands and that myoepithelial cells have low proliferative activity in both the normal and atrophic condition of rat sublingual glands.
    Materialart: Digitale Medien
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  • 9
    Digitale Medien
    Digitale Medien
    Copenhagen : Munksgaard International Publishers
    Journal of periodontal research 36 (2001), S. 0 
    ISSN: 1600-0765
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: The cemento-dentinal junction was examined in human maxillary incisors, canines and premolars by scanning electron microscopy combined with NaOH maceration. The NaOH maceration was used to remove interfibrillar substances and to observe details of the fibrillar architecture. The teeth were half-sectioned longitudinally, demineralized and macerated for 3–4 days or for 10–14 days. In the 3–4 day-macerated specimens, longitudinal sections of the cemento-dentinal junction were examined. In the 10–14 day-macerated specimens, the cementum was detached and the inner cementum surface facing the cemento-dentinal junction was examined. Observations suggested that cemental fibrils intermingle with dentinal fibrils only in places at the cemento-dentinal junction in both acellular and cellular cementum. These structural features were consistent in all kinds of teeth investigated here. Using human molars, we have previously proposed that the adhesion of proteoglycans is a main factor for the cemento-dentinal attachment and that the fibril intermingling between dentin and cementum is an accessory or secondary factor. The present study suggests that this applies to other kinds of human teeth.
    Materialart: Digitale Medien
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  • 10
    Digitale Medien
    Digitale Medien
    Copenhagen : Munksgaard International Publishers
    Journal of periodontal research 35 (2000), S. 0 
    ISSN: 1600-0765
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: The cemento–dentinal junction was studied in acellular and cellular cementum of human mandibular third molars by scanning electron microscopy combined with NaOH-maceration. Scanning electron microscopy with NaOH-maceration was applied to observe the fibrous structure in detail through long sections of the cemento–dentinal junction. In macerated specimens, the cemento–dentinal junction was a fibril-poor groove. Some cemental fibrils or fibril bundles penetrated the groove and appeared to intermingle with dentinal fibrils. Prolonged maceration caused detachment of the cemento–dentinal junction irrespective of fibril intermingling allowing observation of the inner cementum surface facing the root dentin. Observations suggested that the fibril intermingling was point-like and present only in places at the cemento–dentinal junction. It was established that NaOH-maceration removes interfibrillar substances effectively in connective tissues and does no damage to the collagen fibril structure and architecture. This study showed the 3-dimensional fibrous structure of the cemento–dentinal junction in human mandibular third molars, and suggested that interfibrillar adhesive substances are more important than the fibril intermingling for the cemento–dentinal attachment.
    Materialart: Digitale Medien
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